Mass transfer attitude-control for space vehicles



May 28, 1963 R. s. MIKSCH 3,091,417

MASS TRANSFER ATTITUDE-CONTROL FOR SPACE VEHICLES Filed Dec. 19, 1960 IN V EN TOR: 20501411 5. Memo @QFLW ATTORNEYS United States Patent 3,091,417 MASS TRANSFER ATTITUDE-CONTROL FOR SPACE VEHICLES Russell S. Miksch, Redwood City, Calif., assignor to American Radiator & Standard Sanitary Corporation, New York, N.Y., a corporation of Delaware Filed Dec. 19, 1960, Ser. No. 76,573 14 Claims. (Cl. 244-76) This invention relates to and in general has for its object the provision of an attitude-control device for space vehicles.

In the operation of space vehicles it is necessary to maintain them properly oriented with respect to their yaw, pitch and roll axes. To attain this end, sensors have been developed for sensing the attitude of space vehicles with respect to these axes, and likewise control devices have been developed responsive to said sensors for correcting the attitude deviation of space vehicles relative to said three reference axes.

More specifically, one of the objects of this invention is the provision of an attitude-control device wherein a body of liquid can be bodily translated in either direction within a conduit mounted on a space vehicle in response to an attitude deviation in the vehicle as reflected by an attitude-sensor also mounted on the vehicle.

Another object of this invention is the provision of an attitude-control device of the character above described wherein each end of said conduit adjoins a vapor-generator separated from said conduit ends only by a common movable wall in the form of a Sylphon, diaphragm or piston, and wherein each of said vapor-generators is under the selective control of the attitude-sensor.

Still another object of this invention is the provision of an attitude-control device of the character above described wherein each of said vapor-generators includes a liquid reservoir with valve means selectively actuable under the control of the attitude-sensor and wherein one reservoir of each pair of reservoirs and the movable walls associated therewith co-operate to translate the liquid in said conduit in either direction, and the other pair of reservoirs and their associated movable walls can be alternated with the first pair of reservoirs to likewise translate said liquid in either direction.

A further object of this invention is the provision of a control device of the character above described wherein said conduit is endless and preferably of circular configuration, wherein a pair of control valves are disposed in said endless conduit and serve to divide said conduit into first and second conduit sections, and wherein each of such sections can be selectively connected through control valves with either one of two expansible chambers, all to the end that one expansible chamber of each pair of expansible chambers can be made to translate liquid through its said conduit section in either direction into the other of its expansible chambers, while the other pair of expansible chambers remain inactive, and vice versa.

Still another object of this invention is the provision of a control device of the character above described wherein one of said vapor-generators can be selectively connected with either one of a pair of opposed valved nozzles so that when necessary a vapor jet can be forced out of one nozzle, thereby to produce a thrust in the opposite direction.

The invention possesses other advantageous features, some of which, with the foregoing, will be set forth at length in the following description where that form of the invention which has been selected for illustration in the drawings accompanying and forming a part of the present specification is outlined in full. In said drawings, one form of the invention is shown, but it is to be understood Patented May 28, 1963 that it is not limited to such form, since the invention as set forth in the claims may be embodied in other forms.

Referring to the drawings, the single FIGURE therein shown is a diagrammatic illustration of a control device embodying the objects of my invention.

More specifically, the control device illustrated in this diagram includes an endless conduit of circular configuration and generally referred to by the reference numeral 1. Disposed in the conduit 1 along spaced points thereon are a pair of flow-control valves 2 and 3 and which serve to divide the conduit 1 into opposed conduit sections 4 and 5.

Connected to the conduit section 4 intermediate its ends and by a T 6 are liquid reservoirs 7 and 8. Disposed in the cross member of the T 6 are flow-control valves 9 and 11. Mounted adjacent the reservoir 7' is a pressurizer or vapor-generator generally indicated by the reference numeral 12, and separating the vapor-generator 12 from its associated reservoir 7 is a common movable wall here shown in the form of a Sylphon 13. Similarly, the reservoir 8- is associated with a vapor-generator generally referred to by the reference numeral 14, and with a Sylphon 15. Accommodated in each of the vapor-generators 12 and 14 are liquid-retaining and heat-transfer capillary members 16, these members being saturated with a relatively low-boiling-point liquid 17. The members 16 are here resorted to, to prevent any relative displacement between the vapor-generator and its liquid content and also to effect a better heat-transfer between the liquid 17 and the heaters to be presently described.

Similarly, the conduit section 5' is connected with liquid reservoirs 21 and 22 through a T 23 and through flowcontrol valves 24 and.25. Associated with the reservoir 21 is a vapor-generator 26, and separating the vapor-generator 26 from the reservoir 21 is a Sylphon 27. Accommodated within the vapor-generator 26 is a liquid-retaining sponge 28 saturated with a liquid having a relatively low boiling point. Likewise, the reservoir 22 is operatively associated with a vapor-generator 29 including a sponge 31 and separated from the reservoir by a common movable wall in the form of a Sylphon 32.

Operatively associated with the structure above described is an attitude-sensor unit 33 including a pressurecontrol and related switching circuitry, the design of which is all within the knowledge of those skilled in the art.

Located within each of the sponges of each of the vapor-generators 12, 1-4, 26 and 29 are heating elements 34 connected to the sensor unit 33 respectively through lines 35, 36, 37 and 38. Also mounted in each sponge is a thermostat 39 respectively connected with the sensor I unit 33 throughlines 41, 42, 43 and 44.

The flow-control valves 2 and 3 are respectively connected to the sensor unit 33 through lines 45 and 46. And the reservoir flow-control valves 9, 11, 24 and 25 are respectively connected with the sensor unit 33 through lines 47, 48, 49 and 51.

Optionally one of the vapor-generators, for example the generator 26, can be connected through a thermally insulated T 52 and flow-control valves 53 and 54 with opposed jet nozzles 55 and 56. The valves 53 and 54 are under the selective control of the sensor unit 33 and to that end are connected therewith by lines 57 and 58.

As is readily apparent, the flow-control valves 9 and 11 can be consolidated into a single three-way valve, and the same thing can be done with the flow-control valves 24 and 25.

Completely filling the conduit 1, the Ts 6 and 23 and the reservoirs 7, 8, 21 and 22 is a body of liquid 59 having a boiling point substantially higher than the boiling point of the liquid 17 contained in the vapor-generar a 3 tors. For example, water and alcohol as the latter.

Preferably the control device as above described is so mounted on a space vehicle 61 that the center of mass of the device contains the reference inertial axis 62 in question, either the yaw, pitch or roll axis. And the plane of the control device should be normal to such axis. If the space vehicle is of spherical configuration, the diameter of the conduit 1 should be substantially as large as a diameter of the vehicle.

If either the valves 2 or 3 be fully closed, the conduit 1, instead of being endless, becomes closed-ended. As previously indicated, it is not necessary that the conduit 1 be either endless or of circular configuration. As a matter of fact, a straight closed conduit will suflice.

In eifect the structure herein described includes two duplicate systems for alternate use in correcting attitude deviations in response to signals for the attitude-sensor 33. To this end the reservoir 7 and its associated vaporgenerator 12 and the diametrically opposed reservoir 22 and its associated vapor-generator 29 serve as the first system. The second system includes the other diametrically opposed reservoirs 8 and 21 and their associated vapor-generators. When the first system is active the second system is inactive, and vice versa.

Each system can be made to translate liquid through the conduit 1 in either a clockwise direction or a counterclockwise direction by selectively opening the valves 2 and 3.

For example, assume that the reservoirs 7 and 22 are first to be used and that the other pair of reservoirs 8 and 21 are in an inactive or standby condition. Further assume that the reservoir 7 is at a high pressure and that the reservoir 22 is at a low pressure. If then the valves 9, 3 and 25 are opened under the control of the sensor 33, liquid in the system will be translated in a clockwise direction from the high-pressure reservoir 7 to the low-pressure reservoir 22. If, conversely, the valve 2 is opened rather than the valve 3, the mass transfer will proceed in a counterclockwise direction from the high-pressure reservoir 7 to the lower-pressure reservoir 22. But the liquid system of the reservoirs 7' and 22 has a limited mass-transfer capacity and when this system has become exhausted the roles of the two systems must be reversed as sensed by the sensor 33. In the meantime the heater 34 has been activated so as to pressurize the reservoir 8, thus readying the second system constituted by the high-pressure reservoir 8 and its companion low-pressure reservoir 21 for use. Immediately upon the deactivation of one system, the role of its two vapor-generators is reversed-that is, the heater of the previously high-pressure reservoir is deactivated and the heater of the previously low-pressure reservoir is activated'.

As a result of these two systems which, due to the valves shown, can be considered as two independent systems, each system can be used to correct either a clockwise (CW) or counterclockwise (CCW) disturbance in the vehicle. If a clockwise disturbance occurs, the then active system can be utilized to effect a counterclockwise corrective impulse by a clockwise transfer of the liquid in the conduit 1. If a counterclockwise disturbance of the vehicle occurs, the liquid is made to travel in the opposite direction. If the mass transfer efiected in this manner is insufiicient to correct the deviation in question, then the two systems are interchanged and corrective action iscontinued as needed. If a substantially diiferent or permanently changed angular rate is desired, then one or the other of the jet nozzles 54 and 55 is brought into play so as to produce the appropriate change.

It should here be observed that at all times there is sufiicient vapor pressure in even the lower-pressure generators to cause a jet of vapor to escape to atmosphere through one of the open nozzles 54 and 55 to supplementthe mass transfer taking place through the conduit can be used as the former 1. In other words, none of the vapor-generators is at any time entirely passive. This is of course determined by the vapor-generator heaters and their associated thermostats 39, which are under the control of the attitudesensor 33, as are all of the valves illustrated.

Mass transfer of the liquid in the tube 1 when valve 2 or 3 is opened results from a pressure differential maintained Within the system by thermal control of vapor pressures in the expansible or contractible chambers.

So long as no attitude change is directed by the attitude control unit, all valves maintain their status quo.

Although for purposes of illustration the four reservoirs have been paired off diagonally, they can just as well be paired off vertically.

Although the general theory of operation of this device should be clear from the above description, it might be further noted that as a result of the natural laws relating to the conservation of angular momentum, the angular displacement 0,, of the vehicle can be shown to be related to the apparent angular displacement 6;- (as seen from the vehicle) of the mass of liquid transferred by the expression:

' placement of the vehicle is opposite in direction to that of the liquid transferred. During the process of liquid transfer, the change Aw in rotational rate of the vehicle is related to the apparent change Am in rotational rate (as seen from the vehicle) of the mass of liquid in motion in the passageway by the expression:

Thus, vehicle rotation can be sustained as long as liquid flow can be sustained by the liquid remaining in the highpressure reservoir. A permanently changed rotational rate can be produced by activating the appropriate nozzle valve 54 or 55. Control of rate changes can be obtained by control of pressure difference between the highand low-pressure reservoirs, or by controlling the extent of opening of the valve; in either case, flow velocity will adjust itself so that the resulting pressure drop between the reservoirs will equal the pressure differential then existing.

It When all liquid has been transferred from the highpressure reservoir to the low-pressure reservoir an attitude deviation still obtains, further correction may be obtained by activating the then-inactive system and deactivating the now-exhausted system.

Additional passageways between the same reservoirs but arranged about other axes can be employed to provide simultaneous control about more than one axis. Duplicate systems can be employed to prevent net redistributions of mass that might otherwise affect the equilibrium of the vehicle. The vapor-generating compartments of the reservoirs can be employed with vapor jets discharging externally to produce permanently changed angular rates of the vehicle.

I claim:

1. A mass transfer attitude-control device comprising: first and second spaced liquid storage reservoirs interconnected by a liquid conduit; a control valve disposed in said conduit intermediate said first and second reservoirs; first and second expansible chambers respectively disposed in said first and second reservoirs; first and second vapor-generators respectively communicating with said first and second expansible chambers; means for selectively activating said first and second vapor-generators and means for actuating said control valve.

2. A mass transfer attitude-control device of the character set forth in claim 1 wherein said conduit and said reservoirs are completely filled with a liquid.

3. A mass transfer attitude-control device of the character set forth in claim 1 wherein said vapor-generator contains a liquid having a boiling point lower than the boiling point of the liquid contained in said conduit and reservoirs.

4. A mass transfer attitude-control device comprising: an endless conduit; a pair of control valves disposed at spaced points in said endless conduit and dividing said conduit into first and second conduit sections; first and second liquid storage chambers respectively communicating with said first and second conduit sections; first and second expansible fluid chambers respectively disposed in said first and second storage chambers; first and second vapor-generators respectively communicating with said first and second expansible fluid chambers; means for selectively actuating said control valves; and means for selectively activating said vapor-generators.

5. A mass transfer attitude-control device of the character set forth in claim 4 wherein said conduit sections and their associated reservoirs are completely filled with a liquid.

6. A mass transfer attitude-control device of the character set forth in claim 4 wherein said vapor-generators contain a liquid having a boiling point lower than the boiling point of the liquid in said conduit sections and their associated reservoirs.

7. A mass transfer attitude-control device comprising: first and second spaced pairs of liquid reservoirs; a liquid conduit; means for selectively establishing communication between said conduit and each of said reservoirs; an expansible chamber disposed in each of said reservoirs; a vapor-generator communicating with each of said expansible chambers; and means for selectively activating each of said vapor-generators.

8. A mass transfer attitude-control device for space vehicles comprising: a conduit; a body of liquid disposed in said conduit; pressure-responsive means at each end of said conduit for bodily translating said liquid along said conduit; temperaturenresponsive means for selectively actuating each of said pressure-responsive means; and means for selectively actuating said temperature-responsive means.

9. A mass transfer attitude-control device for space vehicles comprising: an attitude-sensor; a conduit; a body of liquid disposed in said conduit; pressure-responsive means at each end of conduit for selectively translating said body of liquid along said conduit in either direction; temperature-responsive means for selectively actuating said pressure-responsive means; said temperature-respon sive means being under the selective control of said attirude-sensor.

10. A mass transfer attitude-control device comprising: an attitude-sensor; a conduit; a first reservoir communicating with one end of said conduit; a second reservoir communicating with the other end of said reservoir; a first vapor-generator contiguous to said first reservoir; a second vapor-generator contiguous to said second reservoir;

a first Sylphon disposed between said first reservoir and said first vapor-generator and forming a common movable wall therebetween; a second Sylphon disposed between said second reservoir and said second vapor-generator and forming a common movable wall therebetween; and means responsive to said attitude-sensor for selectively activating said first and second vapor-generators.

11. A mass transfer attitude-control device comprising: an attitude-control sensor; a conduit; first and second reservoirs connected to one end of said conduit; third and fourth reservoirs connected to the other end of said conduit; first valve means for selectively controlling the flow of liquid between said first and second reservoirs and said conduit; second valve means for selectively controlling the flow of liquid between said third and (fourth reservoirs and said conduit; said first and second valve means being under the selective control of said attitudesensor; a vapor-generator contiguous to each of said reservoirs; and a Sylphon mounted between each of said reservoirs and its contiguous vapor-generator and forming a common movable wall therebetween, each of said vaporgenerators being under the selective control of said attitude-sensor.

12. A mass transfer attitude-control device comprising: an attitude-sensor; an endless conduit; first and second control valves interposed in said conduit along spaced points thereon, said valve dividing said conduit into first and second conduit sections; a first reservoir connected to said first conduit section through a first reservoir control valve; a second reservoir connected to said second conduit through a second reservoir control valve, said first and second reservoir control valves being under the selective control of said attitude-sensor; a vapor-generator contiguous to each of said reservoirs; and a Sylphon mounted between each of said reservoirs and its contiguous vapor-generator and forming a common movable wall therebetween, each of said vapor-generators being under the selective control of said attitude-sensor.

13. A mass transfer attitude-control device of the character set forth in claim 1 wherein one of said vapor-generators communicates with a pair of opposed jet nozzles and wherein said jet nozzles are under the selective control of said means.

=14. A mass transfer attitude-control device of the character set forth in claim 10 wherein one of said vaporgenerators is in communication with a pair of opposed jet nozzles and wherein said jet nozzles are under the selective control of said attitude-sensor.

References Cited in the file of this patent UNITED STATES PATENTS 2,258,464 Moody Oct. 7, 1941 2,774,305 Fitzgerald Dec. 18, 1956 2,856,142 Haviland Oct. 14, 1958 FOREIGN PATENTS 685,486 France July 10, 1930 575,683 Great Britain Feb. 28, 1946 

1. A MASS TRANSFER ATTITUDE-CONTROL DEVICE COMPRISING: FIRST AND SECOND SPACED LIQUID STORAGE RESERVOIRS INTERCONNECTED BY A LIQUID CONDUIT; A CONTROL VALVE DISPOSED IN SAID CONDUIT INTERMEDIATE SAID FIRST AND SECOND RESERVOIRS; FIRST AND SECOND EXPANSIBLE CHAMBERS RESPECTIVELY DISPOSED IN SAID FIRST AND SECOND RESERVOIRS; FIRST AND SECOND VAPOR-GENERATORS RESPECTIVELY COMMUNICATING WITH SAID FIRST AND SECOND EXPANSIBLE CHAMBERS; MEANS FOR SELECTIVELY ACTIVATING SAID FIRST AND SECOND VAPOR-GENERATORS AND MEANS FOR ACTUATING SAID CONTROL VALVE. 